GREAT VACCINATION EXPECTATIONS
Scientists say Americans expect too much from first COVID- 19 vaccines
The White House and many Americans have pinned their hopes for defeating the COVID- 19 pandemic on a vaccine being developed at “warp speed.” But some experts warn they’re all expecting too much too soon.
“Everyone thinks COVID- 19 will go away with a vaccine,” said Dr. William Haseltine, chair and president of Access Health International, a foundation that advocates for affordable care.
Ongoing clinical trials are primarily designed to show whether COVID- 19 vaccines prevent any symptoms of the disease, which could be as minor as a sore throat or cough. But the trials, which will study 30,000 to 60,000 volunteers, will be too short and too small to prove the vaccines prevent what people fear most — being hospitalized or dying — by the time the first vaccine- makers file for emergency authorization, expected later this year, Haseltine said.
The United States should hold out for an optimal vaccine, with more proven capabilities, Haseltine said. Others say the crushing toll of the pandemic demands that we accept the best vaccine we can get within the next few months.
“There’s a tension between getting every piece of information and getting a vaccine in time to save lives,” said Dr. William Schaffner, a professor of preventive medicine and health policy at the Vanderbilt University Medical Cancer.
“Would we like to know if the vaccine reduces illness or mortality? Of course,” said Dr. Peter Lurie, a former FDA official and current president of the Center for Science in the Public Interest. “But there is a real time pressure.”
“Simply preventing mild cases is not enough and may not justify the risks associated with vaccination,” said Peter Doshi, an associate professor at the University of Maryland School of Pharmacy, who detailed his concerns in an editorial in The BMJ.
But experts say there are good reasons to focus on milder cases. Vaccines that prevent mild disease typically prevent severe disease, as well, said Dr. Arnold Monto, an epidemiologist at the University of Michigan’s School of Public Health.
The original studies of the measles vaccine showed only that it prevented measles, not hospitalizations or deaths, said Dr. Kathleen Neuzil, director of the University of Maryland’s Center for Vaccine Development and Global Health. Later studies found measles vaccines dramatically reduce mortality.
“There simply does not exist an example in vaccinology of vaccines that are effective against mild disease that are not more effective in severe disease,” said Dr. Philip Krause, deputy director of the vaccine office for the FDA’s Center for Biologics Evaluation and Research.
Dr. Paul Offit, who developed the rotavirus vaccine, compares preventing the coronavirus to fighting a fire.
“If you put out a small fire in the kitchen, you don’t have to worry about the whole house catching fire,” said Offit, a member of the FDA advisory committee on vaccines.
Proving a vaccine prevents severe illness and death is harder than showing it protects against mild illness because hospitalizations and deaths are much rarer. That’s especially true among the type of health- conscious people who volunteer for vaccine trials, who are probably more likely than others to wear masks and socially distance, Schaffner said.
The COVID- 19 pandemic has infected at least 8.7 million Americans. Considering that the true number of Americans infected is estimated to be six to 10 times higher than reported, the mortality rate is about 0.6%, said Dr. Amesh Adalja, a senior scholar at the Johns Hopkins University Center for Health Security.
Scientists agree the ideal vaccine would provide sterilizing immunity — preventing not only disease symptoms but also any infection with the virus, said Dr. Corey Casper, a vaccinologist with the Fred Hutchinson Cancer Research Center.
For example, two doses of measles vaccines prevent 97% of people from even becoming infected with that virus.
Few expect COVID- 19 vaccines to be that effective. “We’re trying to lower that bar and determine how much lower is acceptable,” Casper said.
Preventing mild disease could curb disease and prevent illness, Casper said.
“We’re probably not going to have the perfect vaccine,” he said. “But I do think we’re likely to have vaccines that, if we can show they’re safe, can put an inflection point on this pandemic. I think it’s still important to have a vaccine that has some effect even on mild illness.”